This invention relates generally to fuel cell systems and more specifically to fuel cell systems with an efficient sealing arrangement. A fuel cell produces electricity by catalyzing fuel and oxidant into ionized atomic hydrogen and oxygen at, respectively, the anode and cathode. The electrons removed from hydrogen in the ionization process at the anode are conducted to the cathode where they ionize the oxygen. In the case of a solid oxide fuel cell, the oxygen ions are conducted through the electrolyte where they combine with ionized hydrogen to form water as a waste product and complete the process. The electrolyte is otherwise impermeable to both fuel and oxidant and merely conducts oxygen ions. This series of electrochemical reactions is the sole means of generating electric power within the fuel cell. It is therefore desirable to reduce or eliminate any mixing of the reactants that results in a different combination such as combustion, which combustion does not produce electric power and therefore reduces the efficiency of the fuel cell.
The fuel cells are typically assembled in electrical series in a fuel cell assembly to produce power at useful voltages. To create a fuel cell assembly, an interconnecting member is used to connect the adjacent fuel cells together in electrical series. When the fuel cells are operated at high temperatures, such as between approximately 600° Celsius (C) and 1000° C., the fuel cells are subjected to mechanical and thermal loads that may create strain in the fuel cell assembly and affect the seal separating the oxidant and the fuel paths.
Therefore there is a need to design a fuel cell assembly, which assembly is sealed in an efficient way to keep the oxidant and the fuel path separated at high operating temperatures.